Frequent re-installations of operating system due to crashes is always been a problem for many of the linux users, and my case is also the same.... Everytime i start with doing something like trying some new commands or editing some configuration files and finally ends up with an 'OS crash' and a fresh installation thereafter.
While fighting with all these crashes and re-installations the major problem is related to backing up of the data and personal files stored in the /home folder. One of the best solution to avoid this kind of frequent backup-restore problem is separate the /home directory from the root directory during the installation.